Strand monitoring apparatus

ABSTRACT

An apparatus for monitoring a plurality of strand manipulating operations on a machine in order to determine the efficiency of the machine. Each machine is provided with a sensing means that is activated when there is an absence of tension in a strand. The scanner scans all of the sensing means. A counter is provided for counting count pulses when the strands are operating normally. However, if the strand has parted the scanner causes the counting circuit to be interrupted in order to inhibit the counting operation. If the counter does not reach a predetermined value an alarm is sounded.

United States Patent Inventor John M. Cochran, Jr.

Greenville, S.C.

Appl. No. 11,46 4 7 Filed Feb. 16, 1970 Patented Sept. 28, 1971 Assignee Frontier Electronics, Inc.

Greenville, S.C.

STRAND MONITORING APPARATUS Primary Examiner-John Caldwell Assistant Examiner- Michael Slobasky Attorney-Bailey and Dority ABSTRACT: An apparatus for monitoring a plurality of 10 claims 5 Drawing Figs strand manipulating operations on a machine in order to (1.8. CI 340/259, determine the m i f the machine Each machine i /413 vided with a sensing means that is activated when there is an Int. Cl .G08b 21/00 absence f tension in a Swami The Scanner scans a" f the 340/259 sensing means. A counter is provided for counting count pul- 4i3 ses when the strands are operating normally. However, if the strand has parted the scanner causes the counting circuit to be References cued interrupted in order to inhibit the counting operation. lf the UNITED STATE PATENTS counter does not reach a predetermined value an alarm is 3,345,812 10/1967 Pickering 340/259 X sounded.

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JOHN M. COCHRAN,JR. BY

ATTORNEYS STRAND MONITORING APPARATUS This invention relates to an apparatus for monitoring a plurality of strand manipulating operations, and more particularly to an apparatus which generates an alarm when the efficiency of the machine drops below a predetermined level.

It has become the policy of many industries of paying workers incentive wages based on the efficiency of their operation. In order to fairly determine whether the worker's efficiency is adversely effected by a particular machine he is operating, rather than his working ability, it is necessary to know the efficiency of the mechanical operations performed by the machine.

One particular situation where such is applicable is in the textile industry where strand processing means, such as winding machines and twisting machines are utilized. In order for a worker to maintain his own efficiency high it is necessary for him to be alerted when the efficiency of a particular winding machine drops below a predetermined value. If a worker is tying up ends on a machine when an alarm is sounded on another machine indicating that the efficiency of the winding machine has dropped below a predetermined level he can immediately go to that machine and correct the problem. Heretofore, the ends down on a winding machine were physically counted consuming a considerable amount of time.

These winding and twisting machines generally have two sides with a row of spindles down each side. Each spindle is included in an individual strand processing operation, such as placing a false twist in the yarn. It is desirable to know the number of advancing strands on each machine so that the efficiency of the machine can be calculated, as well as the operator's efficiency.

Accordingly, it is an important object of the present invention to provide an apparatus for monitoring a plurality of strand manipulating operations in order to determine the efficiency of the machine.

Still another important object of the present invention is to provide an apparatus for monitoring a plurality of advancing strands on a machine which does not produce false information as a result of a power failure to the machine.

Still another important object of the present invention is to provide an apparatus for monitoring a plurality of strand manipulating operations which generates an alarm responsive to the efficiency of the machine or one segment of the machine dropping below a predetermined value.

Another important object of the present invention is to provide an apparatus for monitoring a plurality of strand manipulating operations that includes a scanner and a counting circuit which has a source of counting pulses interposed therein, the scanning mechanism inhibits the counting pulses each time the tension in a particular strand being monitored is absent.

The construction designed to carry out the invention will be hereinafter described, together with other features thereof.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an ex- .ample of the invention is shown and wherein:

FIG. 1 is a schematic representation of a single strand manipulating operation on a conventional false twist machine provided with conductors for sensing closing of a switching element responsive to parting of the strand;

FIG. 2 is a schematic representation illustrating a scanner scanning a plurality of cutting circuits for respective advancing strands on a strand manipulating machine;

HO. 3 is a schematic diagram illustrating a circuit for monitoring both sides of a strand manipulating machine, such as a false twist machine, or a spinning machine;

HO. 4 is a schematic diagram of a circuit for generating the pulses used in the monitoring apparatus; and

FIG. 5 is an illustration showing the frequency of typical pulses utilized in the circuits.

The drawings illustrate an apparatus for monitoring a plurality of strand manipulating operations, generally designated by the reference Character A, on a machine in order to determine the efficiency of the machine. Each of the strands is under tension during normal operation. A sensing means B is provided for each strand for sensing an absence of tension in the respective strand and generating a signal responsive thereto. A scanner C having a plurality of input terminals and an output terminal is provided for scanning the sensing means B. Means are provided for coupling the sensing means B to the respective input terminals of the scanner C for supplying the signals thereto. Means D is provided for supplying scan pulses to the scanner C for sequentially scanning the input terminals to couple the input terminals to the output terminals during a scan cycle in order to transfer any signals on the input terminals into a serial chain of signals on the output terminals. A counting circuit E is provided and includes a source of count pulses and a counter coupled to the source of count pulses for counting the count pulses. Means G is coupled to the output tenninal of the scanner C and the counting circuit E for inhibiting a count pulse from being supplied to the counter responsive to being activated by a signal on the output terminal of the scanner C. Means is provided for synchronizing the count pulses with the scan pulses so that there is a count pulse supplied to the counting circuit E each time the output terminal is coupled to an input terminal of the scanner C. An alarm circuit; generally designated by the reference character H is provided for being activated responsive to the counter reaching a predetermined count. Thus, at the end of a scan cycle the counter has recorded the number of advancing strands under tension and, if such number drops below a predetermined number, then an alarm is activated to inform an operator in the vicinity.

There are many different types of strand processing machines to which the principles of the present invention may be applied and the present disclosure illustrates the principles for the invention as applied to a false twist machine by way of an example. On most strand manipulating machines, such as a winding machine and a false twist machine, there are driven rolls which cause the yarn to be unwoundfrom a spindle and subsequently taken up on another package. If the yarn breaks between the driven roll and the takeup package, then it is desirable to cut the yarn between the driven rolls and the spindle in order to prevent an accumulation of yarn.

Referring to FIG. 1, there is illustrated schematically a single advancing strand on a false twist machine. The strand 10 is withdrawn from a spindle 11 and twisted by a twisting mechanism 12. It is then drawn within a false twist texturizer 13 wherein heat is applied to the yarn to produce stretch yarn. After the strand 10 leaves the false twist texturizer it is untwisted as at 14 and is collected on a takeup package 15. It is noted that a switching element B engages the advancing strand 10 for sensing the tension therein. If the strand breaks between the false twist texturizer l3 and the takeup package 15, there will be an absence of tension therein, and a spring l5a causes the switching element to close brining such in contact with the terminal 16. The sensing means B is connected in series by lead 17 to a solenoid operated cutter l8, and the secondary winding 19 of a transformer. The primary winding 20 of the transformer is connected to any suitable power source 21. The transformer 20a steps the input voltage down in one particular embodiment to approximately 12 volts on the secondary winding. Thus, when there is absence of tension in the strand 10 between the false twist texturizer l3 and the takeup package 15 the sensing element B is closed by the spring causing 12 volts to be applied to the solenoid operated cutter mechanism l8. This cutter mechanism 18, in turn, cuts the strand between the false twist texturizer and the spindle 11 thus, preventing the yarn from being withdrawn from the spindle 11. The structure of FIG. 1 described above is conventional, and-is merely described to establish the environment in which the monitoring device can be operated.

In order to sense such operation leads 22 and 23 are coupled to terminals 24 and 25, respectively, on opposite sides of the switching element B. Thus, when the strand 10 is advancing properly under normal tension and the switching element B is open there will be a voltage of approximately 12 volts across leads 22 and 23. However, when the switching element B is closed as a result of there being an absence of tension in strand 10, there is a substantially zero voltage signal across leads 22 and 23 since the closing of switching element B provides a short circuit between the leads 22 and 23.

It is desirable to utilize a no voltage signal when there is an absence of tension in the yarn since there are no false signals recorded when the machine is shut down cutting off the voltage to the entire monitoring circuit. If the two leads 22 and 23 were coupled across the solenoid winding 18 and 12 volts were present, it would mean that the strand was not advancing, but if there were no voltage across the solenoid winding 18 it would mean that either the switching element B were open and the yarn is running, or the power is off the machine which would give a false indication.

Lead 22 is coupled to one input terminal of the stepping scanner C. Lead 23 is referred to as a common lead, and is coupled directly to the monitoring circuit, as will be discussed later.

FIG. 2 illustrates a plurality of cutting circuits and the manner in which they are coupled to the input terminals 26 of the scanner C. It is noted that the cutting circuit for a group of advancing strands which are being processed are coupled in parallel with a respective secondary winding 19 of a transformer 20a. The leads which connect one side ofa particular switching element B to a particular input terminal 26 of the scanner are 22, 22a, 22b, etc., while the common lead from each of the group of cutting circuits is 23, 23a, 23b, etc.

The scanner C is a conventional telephone stepping scanner which is stepped sequentially by a scan pulse fed in over lead 27 through the switch S and the scanner stepping coil 27a. The scanner illustrated has a plurality of banks of input terminals 26 to which a respective lead 22, 22a, 22b, etc. is coupled. The banks of input terminals and movable arms 28 are conveniently divided up so that one set of movable arms 28 and bank of input terminals can be used for the spindles and advancing strands on one side of the false twisting machine, while a movable arm 28 and the remaining input terminals 26 can be used for the otherside. As can be seen in FIG. 3, the monitoring circuit is duplicated and one portion is for the left side of the twisting machine, while the otherportion is for the right side of the twisting machine. The operation of both sides is identical and the same reference characters are used for similar parts. The scanner C also operates a pair of contact arms 29 and 30 which are in the rest position. That is the position that the scanner is in prior to beginning a scanning cycle.

The scanning operation is under control of a timing clock 34 which is coupled by leads 31 and 32 to any suitable power source 33. The timing clock 34 operates a pair of switches S and S and runs continuously. When a certain predetermined period of time has elapsed following functions occur to begin a scan cycle. Switch S is closed by the timing clock 34 moving to the left. This applies 24 volts DC from the power supply 33 over lead 35 to a reset winding 36 ofa preset counter 37 which is used for the left side of the strand manipulating machine and, also, by means of lead 35a to the reset coil 36 of the counter for the right-hand side of the machine, This causes the preset counters to be reset to zero count. The 24 volts is also applied to a coil 39 of a counter which counts the number of scans. After a few seconds the switch S, opens by moving back to the right and switch S, closes by moving to the left both under control of the timing clock 34. When switch S closes it allows a pulse from the scan pulser D to be fed over lead 27 to the stepping coil 27a of the scanner. The first pulse which comes along from the scan pulser D steps the scanner movable arm 28 to position 1" and this starts a scan. it is to be understood that the contact arm 28 for the right hand side of the twisting machine operates simultaneously with the contact arm 28 for the left-hand side and the operation is identical. Therefore, only the function of the contact arm 28 for the lefthand side of the scanner is discussed. lf when the contact arm 28 is in engagement with terminal 26 to which lead 22 is connected and there is a 12 volt voltage between leads 22 and 23, such will, in turn, place a voltage across terminals 40 and 41 of the full wave rectifier 42. This will, in turn, place a voltage on relay 43 forming a part of the inhibit circuit G. lnhibit circuit G includes a lead 44 which is coupled to terminal 45 of the full wave rectifier and resistor 46 which leads into the relay 43. The other side of relay 43 is, in turn, coupled to terminal 47 of the full wave rectifier 42. It is noted that when the relay 43 is energized by the 12 volt signal such causes the contact 43a in the counting circuit E to be closed, allowing the count pulses from a count pulse source 48 to be fed over lead 49 through resistor 50, closed contact 43a, diode 51, to coil 52 of the preset counter 37. This pulse causes the counter to count one increment indicating that the first advancing strand is operating properly under tension. The other side of the preset counter coil 52 is coupled through lead 53 to ground 54. It is noted that all of the common leads 23, 23a and 23b, which are coupled on the opposite side of the switching element B from lead 22 are connected together to lead 55 and fed to terminal 40 of the full wave rectifier.

After the first count pulse C another scan pulse is applied over lead 27, lead 27b, contact arm 30, to the stepping coil 27a of the scanner. This causes the movable arm 28 to be stepped to the next terminal 26 of the scanner. During the scan cycle contact arms 29 and 30 are in contact with the right-hand terminal, while during the rest period between scans such are in contact with the left-hand terminal. if the switching element to which lead 22a is connected across is closed as a result of there being an absence of tension in that particular strand, then there is a 0" voltage signal applied across leads 22 and 23, and as a result, across terminals 40 and 41, respectively, of the full wave rectifier 42. This, in turn, allows the relay 43 in the inhibiting circuit to be deencrgized. When the inhibited circuit is deenergized by the 0" voltage signal contact arm 43a is opened, opening the counting circuit. When the next count pulse C is applied by the count pulser 48 over lead 49 such is inhibited from energizing the counter coil 52 of the preset counter. Therefore, there is no count recorded on the preset counters 37. It is noted that another counter coil 55 is connected in shunt with the preset counter coil 52 by means of lead 56 and diode 57. This counter coil 55 is for a counter which maintains a total count through all of the scan cycles for a particular side of the machine, whereas, the preset counters 37 are reset after each individual scan cycle. The bottom side of the counting coil 39 which counts the total number of scans, as well as the counting coil 55 which records the total number of strands under tension on a particular side are also connected to ground through leads 53 and 54. Other suitable totalizing means, such as a computer, can be used in place of the counters or in conjunction with the counters for totalizing thenumber of strands running under tension.

The right-hand side of the circuit is provided with count pulse C for its counting circuit E after count pulse C,. An addition counter coil 55a is coupled by leads and 71 through diodes 68 and 69, respectively, to leads S6 for totalizing the number of strands running under tension recorded on counters 55 on both sides of the machine. The other side of coil 55a is coupled to ground through lead 54.

The scan and count pulses are alternately supplied to the scanner C and the counting circuits E, respectively, for stepping the movable arm 28 and supplying count pulses to the counting circuits until the contact arm 28 completes the scan cycle, at which time contact arm 28 returns to its initial rest position. When the contact arm 28 returns to the rest position movable arm 30 shifts to the left breaking the circuit through leads 55 to the stepping coil 27a preventing any additional scan pulses from being supplied to the stepping coil 27a of the scanner. The contact arm 29 returns to the left wherein. a circuit is completed from the scan pulser D, lead 27, switch contact S lead 59, contact am 60, leads 61 through relay 62 to ground. This forms part of an alarm circuit which is energized when the preset counter 37 fails to reach the desired number. This indicates that the efficiency for one side of the false twist machine has dropped below a predetermined setting. When such happens the relay 62 in the alarm circuit is energized closing contact 63. When contact 63 is closed such causes lamp 64 to be fired and illuminated. Lamp 64 is connected in a series circuit by meansof lead 65 to the power supply 33. The other side of lamp 64 is connected through lead 66 to the power supply. Since the relay 62 is being energized by the scan pulses, the contact 63 is opened andclosed by scan pulses causing the lamp 64 to flash in order to attract the operators attention. If the operator happens to be working in another location and sees the lamp flashing, he will know to come to that particular machine as it is running below the desired efficiency.

However, if the preset counter 37 goes beyond the desired number at the end of the scan cycle, then the contact arm 60 is shifted by the preset counter to the right, opening circuit preventing such from being energized. The contact arm 60, as previously mentioned, is under control of the preset counter. The reason that the lamp 64 does not flash during the scanning cycle is that the contact arm 29 is open during the scan cycle preventing the alarm circuit from being energized. As previously mentioned, when the scan cycle is completed then the contact arm 29 shifts back to the left to activate the alarm circuit.

Arc suppression diodes 67 are connected in shunt with the reset coil 36 of the counter 37, as well as alarm relay 62. Isolation diodes 68 and 69 are also carried in leads 70 and 71 on the right-hand side ofthe circuit.

The reason that spaced count pulses C and C are used rather than a single count pulse for both sides is to enable the total counter 55a to count the strands running for both sides. Most counters, such as 550, require a deenergization period between counts.

FIG. 4 is a schematic diagram illustrating the scan pulser D shown in broken lines and count pulser 48. FIG. 5 illustrates the pulses generated throughout the circuit of FIG. 4.

The circuit illustrated in FIG. 4 is operated or energized by a 24 volt signal being applied from the power supply 33 over lead 72. The majority of the components are connected between the 24 volt lead 72 and the ground lead 73. The entire circuit illustrated in FIG. 4 is controlled by a relaxation oscillator, generally designated by the reference character 74,.

to ground lead 73. It is, also, noted that a filtering capacitor 82 is interposed in the leadwhich extends from between resistors 78 and 79 to the ground lead 73.

When a voltage applied to the emitter electrode 83 of the transistor 01 reaches a certain percentage of the voltage across terminals B1 and B2, such causes the unijunctional transistor O1 to switch from nonconducting state to a conducting mode. The capacitor 75 controls this voltage, and such is charged through resistors 76 and 77 to this predetermined percentage. AFter the capacitor 75 reaches this percentage transistor 01 switches on and remains conducting until capacitor 75 discharges. This generates a pulse which is fed into the base electrode of NPN transistor 02 through diode 84. The pulse generated by transistor O2 is shown at the top of FIG. 5.

Transistor O2 is normally off and its collector as shown by the pulse in FIG. 5 stays at a high level until the pulse occurs from transistor Q1 at which point it switches to a low level. The voltage at the low level is about 0" volts and at the high level is about plus 24 volts. When Q2 switches to the low level it provides a base current path for PNP transistor Q3, which turns transistor Q3 on. The collector electrode of transistor Q3 switches to a high level and produces the C, count pulse on lead 49. It is noted that resistors 86 and 87 are connected in series with the collector electrode of transistor 02 and the emitter electrode is coupled to ground lead 73. A base electrode 88 of transistor O3 is coupled in between transistors 86 and 87. The emitter and collector electrodes of transistor 03 are connected in a circuit which extends between lead 72 and ground lead 73 with a resistor 89 interposed therein.

The collector of transistor 02 is coupled by lead 90 to a monostable multivibrator, generally designated by reference character 91, by coupling capacitor 92. Monostable multivibrator 91 operates to give a time-delay between count pulse C and the next or other count pulse C When capacitor 92 couples the pulse from transistor Q2 into NPN transistor Q4 transistor Q4 is switched to the conducting state, as shown in FIG. 5, producing the pulse identified as 04, and its collector goes from high to lowflt stays low for the duration of the time-delay of monostable multivibrator 91. The time-delay of monostable multivibrator 91 is controlled by capacitor 93 connected between the collector electrode of transistor 04 and the base electrode of transistor Q5. It is also noted that a resistor 94 is connected between the collector electrode of transistor Q4 and the capacitor 93 and ground 73. So as to minimize confusion, the purpose of the various capacitors and diodes will be discussed later.

When the collector of transistor Q4 switches back to the high level this signal is coupled through lead 95, capacitor 96, diode 97, to the base electrode 98 of NPN transistor Q6 which forms a part of monostable multivibrator generally designated by reference character 97. When thisoccurs monostable multivibrator 97 switches from high to low and stays low for the duration of the time-delay provided by capacitor 93. The collector electrode of transistor Q6 is tied to the base electrode of PNP transistor Q8 by lead 99 so that when transistor Q6 switches on it, in turn, causes transistor O8 to switch on producing the count pulse C, on lead 100 connected to the collector electrode of transistor Q8. This pulse C remains on for the duration of the time-delay provided in monostable multivibrator 97. When monostable multivibrator 97 switches off the collector of transistor Q6 goes from low back to high. This change is coupled through leads 99, 101 through capacitor 102, diode 97, to'the base electrode of NPN transistor Q9 of monostable multivibrator generally designated by reference character 104. Monostable multivibrator 104 is then switches and the output is from transistor Q11, which is switched on through transistor Q9. The output of transistor 011 is produced on lead 27 and forms the scan pulse. This scan pulse causes the scanner C to step to the next position in sequence when a scan cycle is taking place.

The above operation of the circuit illustrated in FIG. 4 is repeated and the pulses illustrated in FIG. 5 reoccur in the sequence illustrated by the pulse diagram for applying the scan pulses and the count pulses to the monitoring circuit.

The monostable multivibrators 91, 97 and 104 include the conventional resistors, diodes and capacitors of multivibrators, therefore such will be briefly described.

Each of the circuits have a filter resistor 106 which has one side thereof, coupled to lead 72 for tying the b plus from lead 72 into the circuit. The other side of resistor 106 is coupled to junction 107. A filter capacitor 108 is connected between junction 107 and ground 73. These filter capacitors 108 serve no function in the timing of the pulses except to filter and smooth out the DC supply. Resistors 109 are connected to a respective coupling capacitor 92, 96 or 102, and coupling diode 97, to form a differentiating circuit so that the level shift from the collector electrode of the monostable multivibrator of the preceding circuit becomes a pulse going into the base of one of the respective transistors Q4, Q6 or Q9. Resistor 109 also allows capacitor 102 to charge and discharge where diode 97, for example, would only allow it to charge. Capacitor 111 connected between the base electrode of transistors Q4, Q6 and Q9 and ground is a small filtering capacitor which shorts out any transients that might occur. Resistor 1 12a which is interposed between the collector electrode of transistor Q and the base electrode of transistor Q9 acts as a voltage divider with resistor 110 in coupling the collector of transistor Q10 back to the base electrode of transistor Q9 to hold it on for the duration of the time-delay provided by capacitor 93. A similar resistor is included in monostable multivibrators 91 and 97. Resistors 112 interposed between the collector electrode of transistors 010, Q7, Q5 and junction 107 are merely collector load resistors. Resistor 1 13 interposed between junctions 107 and the base electrode of the same transistors is a base resistor. These are standard components in monostable circuits. Resistors 114 connected between junction 107 and the collector electrodes of transistors Q4, Q6 and Q9 are also collector load resistors and the diode 115 interposed in the same circuit blocks any negative spikes which may come in through the power supply so that these cannot switch the monostable circuit on when it shouldn't be. Such a negative spike into the collector of a transistor, for example, Q9 would cause the circuit to be switched on just like a positive spike in through diode 97 would cause it to switch on Resistors 116 connected between the collector electrodes of transistors Q8 and Q11 and ground lead 73 are load resistors for these transistors so that the circuit will operate without the scanner being connected. Resistors 117 and 118 coupled to the base electrodes of transistors Q8 and Q11 operate as a voltage divider, as well as resistors 117 acting as an emitter to base shunt. Resistor 118 is also a base current limiting resistor because when transistors Q6 and Q9 switch on they go very nearly to ground level, therefore, there should be current limiting on the base current. As previously mentioned, resistor 94 allows the timing capacitors 93 to charge and discharge for controlling the delay in the monostable multivibrators 91, 97 and 104. Diodes 119 prevent a base to emitter breakdown on transistors Q5, Q7 and Q10. A filtering capacitor 120 and a resistor 121 are coupled between the collector electrode of transistor Q7 and ground. Diode 122 and resistor 123 connected between leads 72 and 95 provides a load for transistor ()4. Diodes 124 and resistors 125 connected, for example, between lead 100 and ground lead 73 are provided for are suppression for the countercoils.

FIG. 5 shows the various relationships between the pulses. The count pulse C represents the On" time of transistor Q3, which is controlled by the relaxation oscillator, which includes transistor Q1. The time-delay of monostable multivibrator 91 is the On" time of transistor 04 which provides a delay between count pulse C and count pulse C; This delay is necessary so that a totalizing counter 55a can count in the machine circuit pulses for the left side and pulses for the right side. This time-delay is necessary so that the electromagnetic counter can be energized and then deenergized and energized again. The time-delay of monostable multivibrator 97 is the On time of transistor Q6, the low level, and the On time of transistor 08, which is the high level. The time-delay of monostable multivibrator 104 is simply the length of the scan pulse which is the "On time of transistors Q9 and Q11. As illustrated T, is the time between consecutive C count pulses. T is the time between the end of scan pulse and the beginning of the C count pulse for that position.

While a preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.

1. An apparatus for monitoring a plurality of strand manipulating operations on a machine in order to determine the efficiency of said machine, each of said strands being under tension during normal operations, sensing means provided for each strand for sensing an absence of tension in a respective strand and generating a signal responsive thereto, the improvement comprising: a scanner having a plurality of input terminals and an output terminal, means for coupling said sensing means to respective input terminals of said scanner for supplying said signals thereto, means for supplying scan pulses to said scanner for sequentially scanning said input terminals to couple said input terminals to said output terminal during a scan cycle in order to transfer any signals on said input terminals into a serial chain of signals on said output terminal, a counting circuit, said counting circuit including a source of count pulses, and a countercoupled to said source of count pulses for counting said count pulses, means coupled to said output terminal of said scanner and said counting circuit for inhibiting a count pulse from being supplied to said counter responsive to being activated by a signal on said output terminal of said scanner, and means for synchronizing said count pulses with said scan pulses so that there is a count pulse applied to the counting circuit each time the output terminal is coupled to an input terminal of said scanner, whereby a plurality of strands under tension are monitored during each scan cycle.

2. The apparatus as set forth in claim 1, wherein said means coupled to the output terminal of said scanner and said counting circuit includes a relay having a contact interposed between said source of count pulses and said counter.

3. The apparatus as set forth in claim 1, wherein said counter is a preset counter, an alarm circuit including an alarm, said preset counter having a contact interposed in said alarm circuit, and said preset counter causing said alarm to be energized responsive to said counter failing to reach a predetermined count at the end of said scan cycle.

4. The apparatus as set forth in claim 3, wherein said alarm circuit includes a second switching element operated by said scanner for preventing said alarm from being energized during said scan cycle.

5. An apparatus for monitoring the tension of a plurality of advancing strands on a strand processing machine, said machine having a switching element for each advancing strand that is shifted from a first position to a second position responsive to an absence of tension in said strand, such as caused by said strand breaking, a strand cutting circuit including a voltage source and an electrically operated cutting member provided for cutting said strand when there is an absence of tension in said strand adjacent said switching element, said switching element interposed in said strand cutting circuit between said voltage source and said cutting member for maintaining said cutting circuit open when said strand is advancing under tension and closing said cutting circuit to energize said cutting member when said strand is absent tension, the improvement comprising: a scanner having a plurality of input terminals, a movable arm, and an output terminal, means for coupling each of said input terminals to a respective cutting circuit for receiving an electrical signal from said cutting circuit indicating the position of said switching element, a source of scan pulses coupled to said scanner for stepping said movable arm sequentially across said input terminals for successively coupling said electrical signals to said output terminal, a counting circuit including a source of count pulses, and a counter coupled thereto for counting said count pulses, means for synchronizing said scanning pulses with said count pulses so that there is a count pulse produced each time said movable arm is on a respective input terminal of said scanner, means coupled to said output terminal of said scanner and said counting circuit for opening said counting circuit inhibiting said counter from counting said count pulse when said electrical signal from said cutting circuit indicates there is an absence of tension in said advancing strand, whereby at the end of a scan cycle said counter has recorded the number of advancing strands under tension.

6. The apparatus as set forth in claim 5, wherein said counter is a preset counter, said counter having a movable contact that is moved from a first position to a second position responsive to said counter reaching a predetermined count, an alarm circuit including an alarm, and said movable contact interposed in said alarm circuit for deactivating said alarm circuit when said counter reaches said predetermined count.

7. The apparatus as set forth in claim 6, further comprising: a second movable contact means interposed in said alarm circuit, said second movable contact means being operably connected to said scanner for being closed by said scanner at the end of a scan cycle in order to prevent said alarm from being energized before said scanning cycle is completed.

8. The apparatus as set forth in claim 6, wherein said alarm is a lamp, and means for coupling said scan pulses to said alarm circuit at the end ofa scan cycle for causing said lamp to flash when said count has not reached said predetermined count.

9. The apparatus as set forth in claim wherein, said means for coupling each of said input terminals to a respective circuit includes a pair of conductors connected in said cutting circuit on opposite sides of said switching element, said voltage source, electrically operated cutting member, and said switching element being connected in series in said cutting circuit. said switching element normally being open when said advancing strand is under tension so,that there is a voltage drop across said pair of conductors, and when said switching element is closed there is substantially no voltage across said conductors.

10. An apparatus for monitoring the operation of a plurality of advancing strands on a strand processing machine, said machine having a sensing means for each advancing strand for sensing an absence of tension in a respective strand and generating a signal responsive thereto, the improvement comprising: a scanner having a plurality of input terminals and an output terminal, means for coupling said sensing means to respective terminals of said scanner for supplying signals thereto, means for causing said signals on said input terminals of said scanner to be sequentially connected to said output terminal during a scan cycle, a counting circuit, said counting circuit including a source of count pulses and a totalizing means counter coupled to said source of count pulses for totalizing said count pulses, means coupled to said output terminal of said scanner and said counting circuit for inhibiting a count pulse from being supplied to said totalizing means responsive to being activated by a signal on said output terminal of said scanner, and means for synchronizing said count pulses with said scan cycle so that there is a count pulse applied to the totalizing means each time the output terminal is coupled to a respective input terminal of said scanner, whereby a plurality of strands under tension are monitored during each scan cycle. 

1. An apparatus for monitoring a plurality of strand manipulating operations on a machine in order to determine the efficiency of said machine, each of said strands being under tension during normal operations, sensing means provided for each strand for sensing an absence of tension in a respective strand and generating a signal responsive thereto, the improvement comprising: a scanner having a plurality of input terminals anD an output terminal, means for coupling said sensing means to respective input terminals of said scanner for supplying said signals thereto, means for supplying scan pulses to said scanner for sequentially scanning said input terminals to couple said input terminals to said output terminal during a scan cycle in order to transfer any signals on said input terminals into a serial chain of signals on said output terminal, a counting circuit, said counting circuit including a source of count pulses, and a counter coupled to said source of count pulses for counting said count pulses, means coupled to said output terminal of said scanner and said counting circuit for inhibiting a count pulse from being supplied to said counter responsive to being activated by a signal on said output terminal of said scanner, and means for synchronizing said count pulses with said scan pulses so that there is a count pulse applied to the counting circuit each time the output terminal is coupled to an input terminal of said scanner, whereby a plurality of strands under tension are monitored during each scan cycle.
 2. The apparatus as set forth in claim 1, wherein said means coupled to the output terminal of said scanner and said counting circuit includes a relay having a contact interposed between said source of count pulses and said counter.
 3. The apparatus as set forth in claim 1, wherein said counter is a preset counter, an alarm circuit including an alarm, said preset counter having a contact interposed in said alarm circuit, and said preset counter causing said alarm to be energized responsive to said counter failing to reach a predetermined count at the end of said scan cycle.
 4. The apparatus as set forth in claim 3, wherein said alarm circuit includes a second switching element operated by said scanner for preventing said alarm from being energized during said scan cycle.
 5. An apparatus for monitoring the tension of a plurality of advancing strands on a strand processing machine, said machine having a switching element for each advancing strand that is shifted from a first position to a second position responsive to an absence of tension in said strand, such as caused by said strand breaking, a strand cutting circuit including a voltage source and an electrically operated cutting member provided for cutting said strand when there is an absence of tension in said strand adjacent said switching element, said switching element interposed in said strand cutting circuit between said voltage source and said cutting member for maintaining said cutting circuit open when said strand is advancing under tension and closing said cutting circuit to energize said cutting member when said strand is absent tension, the improvement comprising: a scanner having a plurality of input terminals, a movable arm, and an output terminal, means for coupling each of said input terminals to a respective cutting circuit for receiving an electrical signal from said cutting circuit indicating the position of said switching element, a source of scan pulses coupled to said scanner for stepping said movable arm sequentially across said input terminals for successively coupling said electrical signals to said output terminal, a counting circuit including a source of count pulses, and a counter coupled thereto for counting said count pulses, means for synchronizing said scanning pulses with said count pulses so that there is a count pulse produced each time said movable arm is on a respective input terminal of said scanner, means coupled to said output terminal of said scanner and said counting circuit for opening said counting circuit inhibiting said counter from counting said count pulse when said electrical signal from said cutting circuit indicates there is an absence of tension in said advancing strand, whereby at the end of a scan cycle said counter has recorded the number of advancing strands under tension.
 6. The apparatus as set forth in claim 5, wherein said counter is a preset counter, said counteR having a movable contact that is moved from a first position to a second position responsive to said counter reaching a predetermined count, an alarm circuit including an alarm, and said movable contact interposed in said alarm circuit for deactivating said alarm circuit when said counter reaches said predetermined count.
 7. The apparatus as set forth in claim 6, further comprising: a second movable contact means interposed in said alarm circuit, said second movable contact means being operably connected to said scanner for being closed by said scanner at the end of a scan cycle in order to prevent said alarm from being energized before said scanning cycle is completed.
 8. The apparatus as set forth in claim 6, wherein said alarm is a lamp, and means for coupling said scan pulses to said alarm circuit at the end of a scan cycle for causing said lamp to flash when said count has not reached said predetermined count.
 9. The apparatus as set forth in claim 5 wherein, said means for coupling each of said input terminals to a respective circuit includes a pair of conductors connected in said cutting circuit on opposite sides of said switching element, said voltage source, electrically operated cutting member, and said switching element being connected in series in said cutting circuit, said switching element normally being open when said advancing strand is under tension so that there is a voltage drop across said pair of conductors, and when said switching element is closed there is substantially no voltage across said conductors.
 10. An apparatus for monitoring the operation of a plurality of advancing strands on a strand processing machine, said machine having a sensing means for each advancing strand for sensing an absence of tension in a respective strand and generating a signal responsive thereto, the improvement comprising: a scanner having a plurality of input terminals and an output terminal, means for coupling said sensing means to respective terminals of said scanner for supplying signals thereto, means for causing said signals on said input terminals of said scanner to be sequentially connected to said output terminal during a scan cycle, a counting circuit, said counting circuit including a source of count pulses and a totalizing means counter coupled to said source of count pulses for totalizing said count pulses, means coupled to said output terminal of said scanner and said counting circuit for inhibiting a count pulse from being supplied to said totalizing means responsive to being activated by a signal on said output terminal of said scanner, and means for synchronizing said count pulses with said scan cycle so that there is a count pulse applied to the totalizing means each time the output terminal is coupled to a respective input terminal of said scanner, whereby a plurality of strands under tension are monitored during each scan cycle. 